Week 13 (Oct 28 - Nov 1)

Monday

Perks of one circuit in one CD

Length restriction due to PSA dimensions causes cuts in PMMA layer to be very close to each other
During fabrication, the small amounts of melted material in adjacent chambers could cause water to leak
The closeness of the chambers also makes for a troublesome fabrication

The PSA layers incorporation onto the PMMA middle layer was made as fabrication steps, during which some issues were encountered as mentioned above.
Yet another redesign will be made to incorporate one circuit in only one half of the disc.

Design possible with 2mm PMMA layer

Source chamber: 82°, (R=85, r=15), Area=5009.09495mm^2
Air chamber: 82°, (R=120, r=85), Area=5134.322327mm^2

Tuesday

Friday's design, one circuit in CD, works

The idea of having the circuit cover the entire CD was to have the center of mass at the rotation axis
Despite the perks mentioned on Monday, no water leakages were present
Acetate bottom layer was used, and no leakage around the substrate area were present
Flow reciprocation is possible

Complete device as per the design established on Friday, Week 12 (Oct 21 - Oct 25)

Water in the source chamber (bottom right) a few seconds after removing from motor

Water in the source chamber (bottom right) three minutes after rotation

Design improvement

Change the membrane diameter to decrease the reciprocation time

Wednesday

The code was updated for the new design.
The rest of the day was dedicated to other academic activities.

Thursday

There was the intention to make some tests changing the membrane size to see the speed of the reciprocation.
During fabrication, there were some issues, but at the first try, there was no problem.

Fabrication issue

During rotation, the PSA near the fabrication defect starts to come apart. When pressure is applied, it eventually separates and water starts leaking.

Tweak design

It is possible to extend the air chamber to avoid further defects and water flow directly between the chambers (which happened during rotation)

Friday

After the meeting, key activities to do were defined.

Experimental activities

Finalize the device

Reshape (round) the corners of the design to minimize leakage or unwanted fluid transport
Find optimal membrane size for reciprocation based on receding speed

Theoretical (simulation) activities

Finalize code for new design

Update the code, implementing the necessary changes for the new geometries
Validate simulation results with experiments
Extract diagrams/plots/graphs from the resulting data using variations in parameters